Foam stabilizers for phenolic foam

Abstract

The present invention relates to a composition for producing phenolic foam, comprising at least one phenolic resin, at least one blowing agent, at least one catalyst and at least one foam stabilizer according to formula 1. The invention also relates to a method for producing phenolic foam, to phenolic foam produced according to the method, and to the use of the phenolic foam.

Description

[0001] Foam stabilizers for phenolic foam

[0002] The present invention lies in the field of phenolic foams. In particular, it relates to a composition for producing phenolic foam, a process for producing phenolic foam, phenolic foam produced according to the invention, and the use thereof. For the purposes of the present invention, phenolic foam is preferably understood to mean a foam obtainable by reacting a phenolic resin with an acid as catalyst with the addition of a blowing agent and a foam stabilizer. Phenolic foams are known to the person skilled in the art and are described, for example, in EP 3830174 A1, DE 602004006376 T2, EP 2898005 A1, EP 1922357 A1, WO 2022043561 A1, EP 4073155 A1, AU 2021238847 A1, or WO 20061 14777 A1. Phenolic foams are also referred to as phenolic foams, phenolic resin foams, or phenolic resin foams. These terms are used synonymously. This also applies to this invention.

[0003] In the production of phenolic foam, cell-stabilizing or foam-stabilizing additives can generally be used. These are intended to ensure a fine-cell, uniform, and low-interference foam structure and thus have a significant positive influence on the performance properties, in particular, for example, the thermal insulation capacity of the foam. Foam stabilizers can usually be used for this purpose, such as foam stabilizers based on ethoxylated vegetable oils, such as castor oil, as described, for example, in EP 3830174 A1. The use of polyether-modified siloxanes (PES), as described, for example, in WO 2022043561 A1, has proven particularly effective in further improving performance properties. In particular, the combination of ethoxylated vegetable oils and polyether-modified siloxanes leads to excellent performance properties.This combination therefore represents a typically preferred type of foam stabilizer in the production of phenolic foam.

[0004] WO 2004 / 056911 A2 describes, inter alia, the production of closed-cell phenolic foams using polyethersiloxane copolymers as foam stabilizers to improve the aging of thermal conductivity, which are described using the general polysiloxane, polyethylene oxide and polypropylene oxide content.

[0005] WO 2022 / 043561 A1 describes, inter alia, the production of phenolic foams using foam stabilizers based on a mixture of ethoxylated castor oil and polyethersiloxane copolymers with less than 50% polyethylene oxide content, preferably using polyethersiloxane copolymers which have a molecular weight of 9,500 to 25,000 g / mol and an HLB value between 9 and 13.

[0006] The use of polyether-modified siloxanes as foam stabilizers in the presence of acids as catalysts can lead to a degradation of the polyether-modified siloxanes and a subsequent formation of cyclic siloxanes, preferably octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), in particular D4 and D5, which have a negative effect on the properties, in particular the emissions, of the phenolic foam.

[0007] Against this background, the object of the present invention was to provide phenolic foams which have similar performance properties, in particular thermal insulation properties, as the phenolic foams produced with conventional polyether-modified siloxanes, but with regard to emissions associated with the formation of cyclic siloxanes, have no or a lower formation of D4, D5 and / or D6, in particular D4 and / or D5.

[0008] The object is achieved by the subject matter of the invention. The subject matter of the invention is a composition for producing phenolic foam, comprising at least one phenolic resin, at least one blowing agent, at least one catalyst and at least one foam stabilizer according to formula 1,

[0009] (Formula 1) with

[0010] R 1 = hydrogen or a saturated or unsaturated, linear or branched g-bonded radical having 1 to 50 carbon atoms, preferably having 2 to 35 carbon atoms, particularly preferably having 3 to 20 carbon atoms, in which the carbon radical can be interrupted by heteroatoms such as oxygen, nitrogen or silicon and / or one or more radicals R 7 can carry,

[0011] R 2 , R 3 , R 4 , R 5= each independently of one another identical or different, linear, branched or cyclic, monovalent hydrocarbon radicals having 2 to 20 carbon atoms, preferably each independently of one another an ethyl radical, a phenyl radical, hydrogen or a radical of the formula -CH2-OR 8 ,

[0012] R 6 = each independently of one another a linear or branched, monovalent hydrocarbon radical having 1 to 20 carbon atoms, -C(O)CH3 or hydrogen, preferably hydrogen, R 7 = a remainder of formula 2,

[0013] (Formula 2)

[0014] R 8= each independently of one another a linear, branched or cyclic, monovalent hydrocarbon radical having 1 to 20 carbon atoms, preferably each independently of one another an allyl radical, -CH=CH-CH3, a butyl radical, an alkyl radical having 8 to 16 carbon atoms or a phenyl radical which may be substituted by monovalent radicals selected from hydrocarbon radicals having 1 to 4 carbon atoms, a = 0 to 100, preferably 0 to 80, in particular 0 to 60, b = 0 to 100, preferably 0 to 80, in particular 0 to 60, c = 0 to 100, preferably 0 to 80, in particular 0 to 60, d = 0 to 100, preferably 0 to 80, in particular 0 to 60, e = 0 to 100, preferably 0 to 80, in particular 0 to 60, f = 0 to 100, preferably 0 to 60, particularly preferably 0 to 10, where a + b + c > 3, preferably > 6, where d + e > 1, when R 1 less than two R 7 -radicals, g = 1 to 12, preferably 1 to 6, particularly preferably 1 to 4 and most particularly preferably 1 to

[0015] 3, x = 0 to 1.5, preferably 0 to 0.5, particularly preferably 0, and wherein the at least one foam stabilizer according to formula 1 is present in a total amount of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the total phenolic resin used.

[0016] Preferably, according to a particularly preferred embodiment, formula 1 is such that R 2 = hydrogen, R 4 = hydrogen,

[0017] R 3 = hydrogen or a radical of the formula -CH2-OR 8 ,

[0018] R 5 = hydrogen or a radical of the formula -CH2-OR 8 , where one of the two residues R 3 and R 5 hydrogen and the other a radical of the formula -CH2-OR 8 is.

[0019] The subject matter of the invention is associated with numerous advantages. It enables the provision of phenolic foams that meet known requirements. In particular, the phenolic foams possess very good insulation properties and exhibit excellent long-term performance as well as high surface quality. This is advantageously achieved without impairing the other properties of the material and, due to the structure of the foam stabilizer, with little or no formation of cyclic siloxanes, preferably D4, D5 and / or D6, in particular D4 and / or D5. Furthermore, particularly fine-cell, uniform, and low-interference foam structures are enabled. The invention also permits joint use with the alkoxylated vegetable oils known from the prior art.

[0020] The composition according to the invention comprises at least one propellant. Preferably, the at least one propellant is selected from the group consisting of

[0021] • Hydrocarbons with 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and / or n-pentane and

[0022] • halogenated hydrocarbons having 3, 4 or 5 carbon atoms, preferably isopropyl chloride, hydrofluoroolefins and / or hydrohaloolefins, particularly preferably 1234ze, 1234yf, 1224yd, 1233zd(E) and / or 1336mzz.

[0023] According to a particularly preferred embodiment of the invention, the composition according to the invention preferably additionally contains at least one surfactant in a total amount of 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the total phenolic resin used. According to a particularly preferred embodiment of the invention, the at least one surfactant is preferably at least one silicon-free surfactant. According to a further particularly preferred embodiment of the invention, the at least one surfactant is preferably at least one alkoxylated, preferably ethoxylated, vegetable oil, preferably castor oil; the at least one alkoxylated vegetable oil can preferably be present in the composition according to the invention in a total amount of 0.1 to 15 parts by weight, particularly preferably 1 to 10 parts by weight, based on 100 parts by weight of the total phenolic resin used.

[0024] The composition according to the invention necessarily contains at least 4 components, namely at least one phenolic resin, at least one blowing agent, at least one catalyst and at least one foam stabilizer according to formula 1.

[0025] The words "additionally at least one surfactant" are intended to mean that the at least one surfactant is an optional further constituent that differs from the at least one foam stabilizer according to formula 1. The composition according to the invention contains at least one catalyst. Preferably, according to a particularly preferred embodiment of the invention, the at least one catalyst is selected from the group consisting of organic and inorganic acids; more preferably, the at least one catalyst is selected from the group consisting of sulfuric acid, phosphoric acid, benzenesulfonic acid, xylenesulfonic acid, para-toluenesulfonic acid, ethylbenzenesulfonic acid, naphtholsulfonic acid, cumenesulfonic acid, and phenolsulfonic acid.

[0026] Preferably, according to a particularly preferred embodiment of the invention, the at least one catalyst is contained in the composition according to the invention in a total amount of 1 to 30 parts by weight, preferably 1 to 25 parts by weight, particularly preferably 3 to 20 parts by weight, based on 100 parts by weight of the total phenolic resin used.

[0027] The composition according to the invention contains at least one phenolic resin. According to a particularly preferred embodiment of the invention, the at least one phenolic resin preferably has a water content of 1 to 25 wt.%, preferably 4 to 19 wt.%, based on the total phenolic resin used.

[0028] A particularly preferred phenolic foam formulation in the sense of this invention results in a density of 5 to 900 kg / m 3 and preferably has the composition shown in Table 1, which corresponds to a preferred embodiment of the invention:

[0029] Table 1 : Composition of a preferred phenolic foam formulation

[0030] A further object of the present invention is a process for producing phenolic foam, which is carried out using a reaction mixture containing a composition according to the invention as described above, preferably as defined in one of claims 1 to 9.

[0031] For further preferred embodiments and refinements of the process according to the invention, reference is also made to the statements and particularly preferred embodiments already made in connection with the composition according to the invention. The present invention further provides a phenolic foam produced according to the aforementioned process according to the invention, preferably using a composition according to the invention, preferably as defined in one of claims 1 to 9.

[0032] A particularly preferred phenolic foam is one that has a density according to ASTM D1622-20 of 5 to 500 kg / m 3 , preferably 10 to 200 kg / m 3 , particularly preferably from 12 to 100 kg / m 3 This corresponds to a particularly preferred embodiment of the invention.

[0033] Another object of the invention is the use of the phenolic foam according to the invention for thermal insulation.

[0034] Particularly preferred compositions according to the invention are described in more detail below.

[0035] A particularly preferred composition according to the invention contains the following components: at least one phenolic resin, at least one blowing agent, at least one catalyst, at least one foam stabilizer according to the invention according to formula 1, optionally additionally at least one surfactant, optionally further additives, etc.

[0036] The production of phenolic foams is known per se. One or more phenolic resins, preferably one or more so-called resole resins, are used for the production of phenolic foams. Phenolic resins that can be used accordingly, preferably resole resins, are known per se. They can preferably be produced in a known manner by condensing phenol or a phenol-based compound such as cresol, xylenol, para-alkylphenol, para-phenylphenol, resorcinol, or the like, and an aldehyde such as formaldehyde, furfural, acetaldehyde, or the like, preferably under basic conditions, for example by using a catalytic amount of alkali hydroxides, such as sodium hydroxide, potassium hydroxide, or calcium hydroxide, or an aliphatic amine, such as trimethylamine or triethylamine, preferably with an excess of aldehyde.This represents the usual route for the production of phenolic resins, preferably resole resins, whereby the invention is not limited to the chemicals just listed above.

[0037] The molar ratio of phenol groups to aldehyde groups is not subject to any restrictions. The ratio is preferably in a range from 1:1 to 1:3, particularly preferably in a range from 1:1.5 to 1:2.5. Preferably, but not limited to, the phenolic resin has a free aldehyde content of 0.1 wt.% to 0.5 wt.%. This can be determined by potentiometric titration according to ISO 11402:2004 with hydroxylamine hydrochloride.

[0038] Phenolic resins that can be used in foam production are preferably liquids at 25°C and atmospheric pressure, preferably with water concentrations of approximately 1 to 25 wt. %, preferably 5 to 20 wt. %, and have methylol groups as reactive substituents, as described, for example, in EP 0170357 B1. If desired, the viscosity of the phenolic resin can be adjusted, among other things, by the water content. High water contents usually lead to a lower viscosity, thus facilitating both resin handling and mixing during foam production.

[0039] The viscosity of preferably usable phenolic resins at 25°C and atmospheric pressure is preferably in the range from 1000 to 28000 mPa*s and can be determined by conventional methods known to those skilled in the art, such as using a Brookfield viscometer. Fundamentals of the preparation and composition of phenolic resins can be found in the prior art and are described in particular, for example, in EP 3830174 A1, EP 2898005 A1, WO 2022043561 A1, or EP 4073155 A1.

[0040] Blowing agents and their use in the production of phenolic foams are known to those skilled in the art. The use of one or more blowing agents depends fundamentally on the type of system and the application of the resulting phenolic foam. Depending on the amount of blowing agent used, a foam with a high or low density can be produced. For example, foams with densities of preferably 5 kg / m 3 up to 900 kg / m 3 , preferably 5 to 500 kg / m 3, particularly preferably 10 to 200 kg / m 3 , especially 12 to 100 kg / m 3 manufactured according to ASTM D1622-20.

[0041] Particularly preferred propellants have already been described above. As possible blowing agents, preferably one or more of the corresponding compounds which can be used in the production of phenolic foams, such as hydrocarbons having 3, 4 or 5 carbon atoms, preferably cyclo-, iso- or n-pentane, halogenated hydrocarbons such as chlorinated hydrocarbons such as dichloroethane, 1,2-dichloroethene, n-propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, isopentyl chloride, 1,1-dichloroethene, trichloroethene or chloroethene or fluorocarbons (HFC), such as HFC 245fa, HFC 134a or HFC 365mfc, hydrofluoroolefins (HFO) or hydrohaloolefins, preferably 1234ze, 1234yf, 1224yd, 1233zd(E) or 1336mzz and mixtures thereof be used.

[0042] Particularly preferred catalysts have already been described above. Catalysts that can be used for the production of phenolic foams are known to the person skilled in the art from the prior art and are described, for example, in EP 0170 357 A1 or DE 602004006376 T2. Preferably, the conventional organic and inorganic acids known from the prior art can be used. One or more acids can be used. Particularly preferred are sulfuric acid, phosphoric acid, benzenesulfonic acid, xylenesulfonic acid, para-toluenesulfonic acid, ethylbenzenesulfonic acid, naphtholsulfonic acid, cumenesulfonic acid and / or phenolsulfonic acid. Mixtures of several of these compounds can preferably be used as catalysts.The preferred amount of catalyst required for complete reaction is influenced, among other things, by the water content of the phenolic resin and / or, if the catalyst is present as an aqueous solution, by its water content. For example, a higher acid concentration may be required at a higher water content.

[0043] Phenolic foam can be formed in a known manner, preferably by reacting a mixture comprising phenolic resin, blowing agent, foam stabilizer, and catalyst. When a catalyst is added to a mixture of phenolic resin, blowing agent, and foam stabilizer, an exothermic reaction occurs between the methylol groups and phenol, leading to the formation of methylene bridges and crosslinking. Water is released through condensation. The type and amount of acid used, the properties of the blowing agent, and the structure of the foam stabilizer influence the exothermicity of the reaction and the foam formation.

[0044] Foam stabilizers and their use in the production of phenolic foams are generally known to those skilled in the art, as described above. According to the invention, at least one foam stabilizer according to formula 1 is used. In addition, additional foam stabilizers that support foam production can also be used. These compounds are well known in the art. For example, EP 3830174 A1 describes the use of ethoxylated castor oil.

[0045] Optional additives may include one or more of the substances known in the art that are commonly used in the production of phenolic foams, such as viscosity reducers, plasticizers, curing agents, flame retardants, cell-refining additives, fillers, dyes, pigments, and / or fragrances. Suitable optional additives are described, for example, in EP 3830174 A1, US 4444912 A, and EP 1922357 A1.

[0046] Optional fillers include metal hydroxides such as aluminum hydroxide, magnesium hydroxide; metal carbonates such as calcium carbonate, magnesium carbonate, barium carbonate, or zinc carbonate; metal oxides such as aluminum oxide or zinc oxide; or metal powders such as zinc. Monoethylene glycol or polyester polyols, for example, can be used to reduce the viscosity of the phenolic resin. Optional hardeners include compounds with amino groups such as urea or dicyandiamide. Urea is preferred. These can be used during foaming or during the production of the phenolic resin.

[0047] The process according to the invention for producing phenolic foams can be carried out by all known methods. These are known to the person skilled in the art and are described, for example, in EP 3830174 A1.

[0048] Unless otherwise apparent from this description, any preferred or particularly preferred embodiment of the invention may be combined with one or more of the other preferred or particularly preferred embodiments of the invention.

[0049] If ranges, general formulas or classes of compounds are given, these are intended to include not only the corresponding ranges or groups of compounds that are explicitly mentioned, but also all sub-ranges and sub-groups of compounds that can be obtained by removing individual values ​​(ranges) or compounds. If documents are cited within the scope of this description, their content, particularly with regard to the facts in connection with which the document was cited, is intended to be fully included in the disclosure of the present invention. If mean values ​​are given, these are numerical averages unless otherwise stated. If parameters are given that were determined by measurement, the measurements were carried out at a temperature of 23 °C and standard pressure (1 atm = 101325 Pa), unless otherwise stated.

[0050] The following examples serve only to further illustrate the present invention and do not represent any limitation of the present invention.

[0051] Examples:

[0052] Synthesis of the foam stabilizers according to the invention

[0053] 1,1,1,3,5,5,5-Heptamethyltrisiloxane was purchased from Aldrich. The reactions were carried out using the Schlenk technique under nitrogen inerting.

[0054] Production of polyethers PE 1 to PE 7

[0055] Production of PE 1 :

[0056] To produce a polyether, 495.64 g of trimethylolpropane diallyl ether and 9.29 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated to an internal pressure of 100 mbar to remove any volatile components by distillation. 40 g of ethylene oxide were added at 115 °C with stirring and cooling. After a noticeable drop in pressure, a further 1171.7 g of ethylene oxide were metered in continuously over 30 minutes with stirring and cooling at 115 °C and a maximum reactor internal pressure of 3.0 bar (absolute). After complete addition and one hour of post-reaction, the mixture was degassed again, cooled to 95 °C, neutralized with 30% H3PO4 (30 wt.% H3PO4 in water based on the total mass of the solution), and treated with 500 ppm Anox 20 AM® and 6.9 g of saturated NaH2PO4 solution. Water was removed by vacuum distillation, and precipitated salts were filtered off.1626.3 g of a yellow, clear polyether were obtained.

[0057] Production of PE 2:

[0058] To produce a polyether, 374.07 g of trimethylolpropane diallyl ether and 14.03 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated to an internal pressure of 100 mbar to remove any volatile components by distillation. 40 g of ethylene oxide were added at 115 °C with stirring and cooling. After a noticeable drop in pressure, a further 916.0 g of ethylene oxide were added continuously over 45 minutes with stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction was allowed to continue for one hour, a further 380.0 g of allyl glycidyl ether were added continuously over 10 minutes. After a further three-hour reaction time, the mixture was degassed again, cooled to 95 °C and treated with 30% H3PO4 (30 wt.The mixture was neutralized with 500 ppm Anox 20 AM® and 6.9 g of saturated NaH2PO4 solution (based on the total mass of the solution). The water was removed by vacuum distillation, and precipitated salts were filtered off. 1704.0 g of a clear, yellow polyether were obtained. Preparation of PE 3:

[0059] To produce a polyether, 392.00 g of trimethylolpropane diallyl ether and 14.70 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated by distillation to an internal pressure of 100 mbar to remove any volatile components. 40 g of ethylene oxide were added while stirring and cooling at 115 °C. After a noticeable drop in pressure, a further 976 g of ethylene oxide were metered in continuously over 50 minutes while stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction continued for one hour, 394.0 g of allyl glycidyl ether were added continuously over 10 minutes, followed by another two hours of post-reaction. A further 665.6 g of propylene oxide were then added continuously over 30 minutes. After a further three-hour reaction time, the mixture was degassed again, cooled to 95 °C and treated with 30% H3PO4 (30 wt.The mixture was neutralized with 500 ppm Anox 20 AM® and 9.9 g of saturated NaH2PO4 solution (based on the total mass of the solution). The water was removed by vacuum distillation, and precipitated salts were filtered off. 2372 g of a clear, yellow polyether were obtained.

[0060] Production of PE 4:

[0061] To produce a polyether, 190.00 g of allyl alcohol and 22.9 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated to an internal pressure of 100 mbar to remove any volatile components by distillation. 40 g of ethylene oxide were added while stirring and cooling at 115 °C. After a noticeable drop in pressure, a further 1545 g of ethylene oxide were added continuously over one hour while stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction was allowed to continue for one hour, 612.7 g of allyl glycidyl ether were added continuously over 30 minutes. After a further three-hour reaction time, the mixture was degassed again, cooled to 95 °C, neutralized with 30% H3PO4 (30 wt.% H3PO4 in water based on the total mass of the solution) and treated with 500 ppm Anox 20 AM® and 9.6 g saturated NaH2PO4 solution.Water was removed by vacuum distillation, and precipitated salts were filtered off. 2392 g of a clear, yellow polyether were obtained.

[0062] Production of PE 5:

[0063] To produce a polyether, 160.00 g of butanol and 15.1 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated by distillation to an internal pressure of 100 mbar to remove any volatile components. 40 g of ethylene oxide were added while stirring and cooling at 115 °C. After a noticeable drop in pressure, a further 1005 g of ethylene oxide were metered in continuously over 45 minutes while stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction continued for one hour, 678 g of allyl glycidyl ether were added continuously over 30 minutes, followed by another two hours of post-reaction. Subsequently, 686.5 g of propylene oxide were added continuously over 35 minutes. After a further three-hour reaction time, the mixture was degassed again, cooled to 95 °C and treated with 30% H3PO4 (30 wt.The mixture was neutralized with 500 ppm Anox 20 AM® and 10.3 g of saturated NaH2PO4 solution (based on the total mass of the solution). The water was removed by vacuum distillation, and precipitated salts were filtered off. 2528 g of a clear, yellow polyether were obtained.

[0064] Production of PE 6:

[0065] To produce a polyether, 190.00 g of butanediol and 14.8 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated by distillation to an internal pressure of 100 mbar to remove any volatile components. 40 g of ethylene oxide were added while stirring and cooling at 115 °C. After a noticeable drop in pressure, a further 981 g of ethylene oxide were metered in continuously over 40 minutes while stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction was allowed to continue for one hour, 926 g of allyl glycidyl ether were added continuously over 30 minutes, followed by another two hours of post-reaction. Subsequently, 673.5 g of propylene oxide were added continuously over 35 minutes. After a further three-hour reaction time, the mixture was degassed again, cooled to 95 °C and treated with 30% H3PO4 (30 wt.-% HsPO4 in water based on the total mass of the solution) and mixed with 500 ppm Anox 20 AM® and 11.3 g of saturated NaH2PO4 solution. Water was removed by vacuum distillation, and precipitated salts were filtered off. 2707 g of a yellow, clear polyether were obtained.

[0066] Production of PE 7:

[0067] To produce a polyether, 270.00 g of trimethylolpropane diallyl ether and 10.12 g of potassium methylate were placed in a 3-liter autoclave under nitrogen. The mixture was then heated to 115 °C with stirring, and the reactor was evacuated by distillation to an internal pressure of 100 mbar to remove any volatile components. 40 g of ethylene oxide were added at 115 °C with stirring and cooling. After a noticeable drop in pressure, a further 1356 g of ethylene oxide were metered in continuously over one hour with stirring and cooling at 115 °C and a maximum internal reactor pressure of 3.0 bar (absolute). After the addition was complete and the reaction was allowed to continue for one hour, 271.9 g of allyl glycidyl ether were added continuously over 10 minutes, followed by another two hours of post-reaction. Subsequently, a further 457.1 g of propylene oxide was added continuously over 25 minutes.After a further three hours of post-reaction, the mixture was degassed again, cooled to 95 °C, neutralized with 30% H3PO4 (30 wt.% HsPO in water based on the total mass of the solution), and treated with 500 ppm Anox 20 AM® and 9.6 g of saturated NaH2PO4 solution. Water was removed by vacuum distillation, and precipitated salts were filtered off. This yielded 2463 g of a clear, yellow polyether, which crystallized upon cooling.

[0068] Production of polyether-modified siloxanes PES 1 to PES 7

[0069] Production of PES 1 :

[0070] 212 g of PE 1 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 87 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected.

[0071] Production of PES 2:

[0072] 185 g of PE 2 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 115 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected.

[0073] Production of PES 3:

[0074] 195 g of PE 3 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 105 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected. Preparation of PES 4:

[0075] 183 g of PE 4 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 117 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected.

[0076] Production of PES 5:

[0077] 215 g of PE 5 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 85 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected.

[0078] Production of PES 6:

[0079] 201 g of PE 6 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 99 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected.

[0080] Production of PES 7:

[0081] 217 g of PE 7 were placed in a 500 mL three-neck flask equipped with a precision glass stirrer, reflux condenser, and dropping funnel and heated to 90 °C. Then, 0.1 g of a toluene solution of the Karstedt catalyst (w (Pt) = 1.5%) was added. 83 g of 1,1,1,3,5,5,5-heptamethyltrisiloxane were added over a period of 75 min. An exothermic reaction began. The reaction mixture was kept at temperatures below 100 °C by cooling. The reaction mixture was then stirred at 90 °C for two hours. A clear, liquid product was obtained in which no SiH functions could be detected. Preparation of the phenol foam

[0082] The formulation shown in Table 2 was used for the application-related comparison. The comparative foamings were carried out using the hand-mixing method. For this purpose, phenolic resin (batch quantity 180 ± 5 g) and foam stabilizer were weighed into a beaker and mixed using a plate stirrer (6 cm diameter) for 15 min at 20 °C and 500 rpm. The blowing agent was then added, mixed for 30 s at 1500 rpm, and then cooled to 18 °C. The acid was then added, the mixture was stirred at 2000 rpm for 45 s, and transferred to a 25 cm x 25 cm x 7 cm aluminum mold thermostatted to 50 °C and lined with polyethylene film. After 1 h, the foams were demolded and cured for 18 h in an oven heated to 60 °C.

[0083] The pore structure was assessed subjectively on a scale of 1 to 10, with 10 representing (idealized) undisturbed, very fine foam and 1 representing extremely disturbed, coarse foam. The thermal conductivity (A-value in mW / m K) was measured on 2.5 cm thick panes using a Hesto Lambda Control device, model HLC X206, at an average temperature of 10°C according to the specifications of EN 12667:2001. The density was determined according to ASTM D1622-20.

[0084] The foam stabilizers of the invention were tested both individually and in combination with an alkoxylated castor oil. TAGAT® CH 40, an ethoxylated castor oil from Evonik Operations GmbH, was used. The results are presented in Tables 3 and 4.

[0085] Table 2: Formulation for the production of phenolic foam

[0086] Phenolic resin Cellobond J6014L from Bakelite. Table 3: Properties of phenolic foams

[0087] Table 4: Properties of phenolic foams

[0088] The results show that all foam stabilizers according to the invention can achieve foam qualities that are at the same level as, or slightly superior to, those of non-inventive foam stabilizers. All other foam properties relevant to use are not, or only insignificantly, affected by the foam stabilizers according to the invention.

Claims

Patent claims 1. Composition for producing phenolic foam, comprising at least one phenolic resin, at least one blowing agent and at least one catalyst, characterized in that the composition additionally contains at least one foam stabilizer according to formula 1, (Formula 1) with R 1 = hydrogen or a saturated or unsaturated, linear or branched g-bonded radical having 1 to 50 carbon atoms, preferably having 2 to 35 carbon atoms, particularly preferably having 3 to 20 carbon atoms, in which the carbon radical can be interrupted by heteroatoms such as oxygen, nitrogen or silicon and / or one or more radicals R 7 can carry, R 2 , R 3 , R 4 , R 5= each independently of one another identical or different, linear, branched or cyclic, monovalent hydrocarbon radicals having 2 to 20 carbon atoms, preferably each independently of one another an ethyl radical, a phenyl radical, hydrogen or a radical of the formula -CH2-OR 8 , R 6 = each independently of one another a linear or branched, monovalent hydrocarbon radical having 1 to 20 carbon atoms, -C(O)CH3 or hydrogen, preferably hydrogen, R 7 = a remainder of formula 2, (Formula 2) R 8= each independently of one another a linear, branched or cyclic, monovalent hydrocarbon radical having 1 to 20 carbon atoms, preferably each independently of one another an allyl radical, -CH=CH-CH3, a butyl radical, an alkyl radical having 8 to 16 carbon atoms or a phenyl radical which may be substituted by monovalent radicals selected from hydrocarbon radicals having 1 to 4 carbon atoms, a = 0 to 100, preferably 0 to 80, in particular 0 to 60, b = 0 to 100, preferably 0 to 80, in particular 0 to 60, c = 0 to 100, preferably 0 to 80, in particular 0 to 60, d = 0 to 100, preferably 0 to 80, in particular 0 to 60, e = 0 to 100, preferably 0 to 80, in particular 0 to 60, f = 0 to 100, preferably 0 to 60, particularly preferably 0 to 10, where a + b + c > 3, preferably > 6, where d + e > 1, when R 1 less than two R 7 -radicals, g = 1 to 12, preferably 1 to 6, particularly preferably 1 to 4 and most particularly preferably 1 to 3, x = 0 to 1.5, preferably 0 to 0.5, particularly preferably 0, and wherein the at least one foam stabilizer according to formula 1 is present in a total amount of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, particularly preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the total phenolic resin used.

2. Composition according to claim 1, characterized in that R 2 = hydrogen, R 4 = hydrogen, R 3 = hydrogen or a radical of the formula -CH2-OR 8 , R 5 = hydrogen or a radical of the formula -CH2-OR 8 , where one of the two residues R 3 and R 5 Hydrogen and the other a residue of the formula - CH2-OR 8 is.

3. Composition according to one of claims 1 to 2, characterized in that the at least one propellant is selected from the group consisting of Hydrocarbons having 3, 4 or 5 carbon atoms, preferably cyclo-, iso- and / or n-pentane and halogenated hydrocarbons having 3, 4 or 5 carbon atoms, preferably isopropyl chloride, hydrofluoroolefins and / or hydrohaloolefins, particularly preferably 1234ze, 1234yf, 1224yd, 1233zd(E) and / or 1336mzz.

4. Composition according to one of claims 1 to 3, characterized in that at least one surfactant is additionally contained in a total amount of 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the total phenolic resin used.

5. Composition according to claim 4, characterized in that the at least one surfactant is at least one silicon-free surfactant.

6. Composition according to one of claims 4 or 5, characterized in that the at least one surfactant is at least one alkoxylated, preferably ethoxylated, vegetable oil.

7. Composition according to one of claims 1 to 6, characterized in that the at least one catalyst is selected from the group consisting of organic and inorganic acids, preferably the at least one catalyst is selected from the group consisting of sulfuric acid, phosphoric acid, benzenesulfonic acid, xylenesulfonic acid, para-toluenesulfonic acid, ethylbenzenesulfonic acid, naphtholsulfonic acid, cumenesulfonic acid and phenolsulfonic acid.

8. Composition according to one of claims 1 to 7, characterized in that the at least one catalyst is present in a total amount of 1 to 30 parts by weight, preferably 1 to 25 parts by weight, particularly preferably 3 to 20 parts by weight, based on 100 parts by weight of the total phenolic resin used.

9. Composition according to one of claims 1 to 8, characterized in that the at least one phenolic resin has a water content of 1 to 25 wt.%, preferably 4 to 19 wt.%, based on the total phenolic resin used.

10. A process for producing phenolic foam, characterized in that it is carried out using a reaction mixture containing a composition as defined in any one of claims 1 to 9.

11. Phenolic foam produced according to the process of claim 10.

12. Phenolic foam according to claim 11, characterized in that the phenolic foam has a density according to ASTM D1622-20 of 5 to 500 kg / m 3 , preferably 10 to 200 kg / m 3 , particularly preferably from 12 to 100 kg / m 3 has.

13. Use of the phenolic foam according to any one of claims 11 to 12 for thermal insulation.

Images